One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,4)(3,7,8,6)(9,10,15,14)(11,19,20,16)(12,22,21,17)(13,18,23,24)(25,26,30,29)(27,31,35,32)(28,36,38,33)(34,40,37,39)(1,3,5,8)(2,6,4,7)(9,11,15,20)(10,16,14,19)(12,13,21,23)(17,18,22,24)(25,27)(26,31)(28,34)(29,32)(30,35)(33,39)(36,40)(37,38)(11,20)(13,23)(16,19)(18,24)(25,27,30,35)(26,32,29,31)(28,37,38,34)(33,39,36,40)(1,2,5,4)(3,6,8,7)(9,12,15,21)(10,17,14,22)(11,13,20,23)(16,18,19,24)(25,27)(26,32)(28,34)(29,31)(30,35)(33,40)(36,39)(37,38)(1,4,5,2)(3,7,8,6)(9,13)(10,18)(11,21)(12,20)(14,24)(15,23)(16,22)(17,19)(25,28)(26,33)(27,34)(29,36)(30,38)(31,39)(32,40)(35,37)(9,14,15,10)(11,16,20,19)(12,22,21,17)(13,18,23,24)(25,29,30,26)(27,31,35,32)(28,33,38,36)(34,40,37,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.